Relationship Between Leptin Level, Inflammation, and Volume Status in Maintenance Hemodialysis Patients

Maintenance hemodialysis (HD) patients often experience fluctuations of volume status. Although hypervolemia possibly induces systemic inflammation, the relationship between volume status and leptin has not yet been well defined. The aims of this study were to determine the levels of leptin, C-reactive protein (CRP), and ferritin in relation to volume status and to assess the relationship between leptin and volume and inflammatory status in chronic HD patients. This prospective study included 93 HD patients divided, based on evaluation using the body composition monitor, into normovolemic and hypervolemic groups (overhydration/extracellular water [OH/ECW] ≤ 15% and OH/ECW > 15%, respectively). The levels of leptin and inflammatory markers (CRP, ferritin) were determined during a mid-week dialysis session in all patients. There were more hypervolemic patients after 12 months of follow up than at baseline (41% vs. 38%). Hypervolemic patients had significantly lower leptin levels (11.42 ± 19.24 ng/mL vs. 34.53 ± 40.32 ng/mL at baseline and 13.41 ± 22.04 ng/mL vs. 41.54 ± 21.78 ng/mL at 12 months), longer time on dialysis, and poorer nutritional status than normovolemic patients. Inflammation was present regardless of the volume status, but hypervolemic patients had significantly higher CRP and ferritin than normovolemic patients. A statistically significant reverse correlation was found between leptin level, hyperhydration index, and OH/ECW. No significant correlation was found between leptin and inflammatory markers CRP and ferritin.